Unimak Pass is believed to be the route 

 used by most eastern Pacific fur seals in 

 moving between the Bering Sea and Pacific 

 Ocean, Smaller passes in the same area are 

 used, although strong tidal currents may affect 

 their use. 



Seals feeding, traveling, and apparently tem- 

 porarily resident were observed. Seals ap- 

 parently traveling were seen in May, June, 

 and early July. The traveling seals during 

 these months were predominantly pregnant 

 females. From late July through early October 

 large concentrations utilized the two main 

 feeding areas. Post partum females predomi- 

 nated in the collection during this period, A 

 resident population of young seals was ob- 

 served throughout the season. 



Data on sex and age of seals collected in 

 Unimak Pass and vicinity are analyzed by 

 10-day periods to show changes in movements 

 of the different classes of seals. 



During June, pregnant females comprised 

 63 percent of the seals collected. In the first 

 10 days of July the percentage dropped to 44, 

 and during the period 11-20 July to only 15. 



Post partum (lactating) females from the 

 Pribilof Islands were first taken in early July, 

 They increased until they formed approxi- 

 mately 50 percent of the collection from 

 August through the first part of October, 

 Some post partum females traveled through 

 Unimak Pass to feed in the area southeast of 

 Tigalda Island. 



Immature females were collected through- 

 out the season. From July through September 

 they composed 70 percent of the seals col- 

 lected southeast of Tigalda Island. 



Nonpregnant females were collected regu- 

 larly throughout the season and comprised 

 about 10 percent of the total. 



Mature bulls were seen or collected through- 

 out most of the season except for the last 

 10 days of June and the first 10 days of July. 

 None was seen after 13 September. Young 

 males were collected throughout the season 

 with no marked changes in abundance. 



No correlation was found between seal 

 movements through the pass and stomach 

 contents or tide direction. The majority of 

 seals collected in the pass had food in the 

 stomach regardless of the time of day or 

 stage of the tide, 



A total of 1,486 seals was collected in 

 1962; 1,354 (91.1 percent) females and 132 

 (8.9 percent) males. Age classes 3 through 11 

 years were best represented. The largest 

 single age classes were those of 4-year 

 females and 3-year males. Yearlings com- 

 prised 0.4 percent of the total collection. 



Fifty seals (3.4 percent) of the total col- 

 lection were found to be carrying tags. One 

 Soviet tag attached in 1960 was recovered. 



For a given age, the average length of 

 pregnant females was greater than that of 

 nonpregnant or post partum females. 



Two hundred eighty-five fetuses were col- 

 lected. 



From 1958 through 1962 the average preg- 

 nancy rate of females 6 through 26 years of 

 age was 83.8 percent. The average pregnancy 

 rate for females taken in pelagic collections 

 during these years was 72.3 percent. 



The youngest pregnant females were 4 years 

 old. Multiparous pregnant females were most 

 numerous through age classes 8 to 12. 



The twin seals collected in 1962 were each 

 smaller than the average normal fetus col- 

 lected at the same time of year. 



The barnacles Lepas pectinata and L. anatifera 

 were attached to guard hairs of two seals. 



Over the past 5 years, more female than 

 male fetuses and more fetuses in the left 

 than in the right uterine horn have been 

 recorded. 



Eleven species of fish and squids were iden- 

 tified in seal stomachs. Excluding cephalopods, 

 few invertebrates have been found in fur seal 

 stomachs. 



57 



